The fluids capable of being distributed in this manner are, generally, cosmetic products, in particular in the field of body care, such as deodorants, hair care products, like lacquer; home care products, such as insecticides and air fresheners; as well as certain pharmaceutical products. Depending on use, the distribution is in the form of creams, mousses, liquid or aerosol sprays.
The most frequently used propulsive products are chlorofluorinated hydrocarbons, known by the trade name "Freon" and sold by Du Pont de Nemours, for example dichlorodifluoromethane.
However, for safety reasons, both during manufacture and before and during use and for reasons of the fight against atmospheric pollution, the use of these propulsive gases, in particular that of the "Freons", is, at the present time, limited or prohibited by the laws of different countries, which poses the problem of discovering new means for ensuring the distribution of the fluids packed in this manner under pressure. In addition, even in the absence of a law prohibiting their use, there is sometimes the problem of preventing the contact of these propulsive gases with the product to be distributed, for reasons of quality or of conformity of said product.